Jack



Patented Dec. 6, 1932 UNITED STATES PATENT OFFICE .TACK

Application 11er! February 10, 1930. Serial No. 427,091.

This invention relates to jacks and more particularly to lifting jacks suitable for automobiles, motor trucks and the like.

It is an object of this invention to provide a jack wherein the thread between a rotatable sleeve anda lifting ram includes roller or ball bearin s.

It is a further object to provide a ack in which the lifting ram is provided with an external peripheral groove in which ride rollers or ball bearings. This invention further aims to provide a jack having a grooved ram, the groove being of only one turn and including portions of opposed inclinations.

still further object is to provide a driving means for a jack of this character, the drivin means includin a handle which is rotata le continuously wile the ram is being elevated but which need be rotated only slightly in order to allow the ram to be lowered. y

It is a further object of the invention to provide driving means for a jack including a clutch permitting continuous rotation of the handle in one direction but permitting only `a partial rotation thereof in the reverse direction'.

Still further objects will readily occur to those skilled in the art u on reference to the following description an the accompanying drawing 1n which:

Fig. 1 shows, in section, a jack and driving means therefor.

Fig. 2 is a section alon the l1ne`22 of Fig. 1, showing specific 1y a clutch stop means.

Figs. 3 and 4 show, diagrammatically, the construction of the groove in the ram.

Referring more specifically to the drawing, Figs. 1 and 2 show a housing in which is mounted a ram having a weight supporting cradle 11 and a. threaded sleeve 12 to cause elevation of the ram and cradle. Means, comprising a handle 13, clutch plates 14 and 15 and gears 16 and 17 are provided to cause rotation of the sleeve'l2 and consequently elevation of the ram 10 and the 'w Acradle 11 associated therewlth.

In the particular construction which I employ the shaft 16 of the cradle is threaded for its entire length in order to be adjustable longitudinally of the ram, the latter being provided with threads 17 engaging, for a portion of their length, the threads ofthe shaft 16 of the cradle. It will be seen that the cradle 11 may be moved in or out of the ram 10' independently of the driving means merely by rotation of the shaft 16 within the'ram. 60 Housing cap member 18 is provided with a pin 19 projecting into the aperture 20 thereof and into longitudinal slots 21 of the ram, permitting reciprocatory movement of the latter but preventing rotary movement there- 55 of with respect to the housing.

, Sleeve l2 is rotatably mounted within the housing 9 upon ball bearings 22 and is internally threaded for its ent-ire length as shown at 23. A plurality of roller or bearing balls 24 are disposed within the sleeve l2 in the threads 23 thereof, balls 24 being between the sleeve 12 and the ram 10. Balls 24 rotate in and travel along the threads 23 in the sleeve 12 to cause elevation of the ram 10 75 `in the hereinafter described manner.

Ram 10 is provided with a .ph eral groove, which, as shown best in 3 and 4, comprises a downwardl inclined, shallow portion 27 and an upwar ly inclined 80 portion 28 connecting the ends of the downwardly inclined portion 27 and considerably deeper than the latter.

`When sleeve 12 is rotated by a driving means hereinafter described, the balls 24 car- S5 ried along therewith will ride in the downwardly inclined portionA 27 of the groove 26 causing elevation of the ram. Taking the case of a single ball 24, for example, the ball will ride in the groove 26 along the down- 99 wardly inclined portion 27, causing elevation of the ram, until it reaches the upwardly inclined portion 28.\ But for the .fact that the upwardly inclined portion 28 is considerably deeper than the other portion aiording a space for the ball to clear the thread 23 `on the sleeve, continued rotation of the latter would then cause lowering of the rain. The clear space enablesthe ball 24 which has reached the upwardly inclined portion 28 103 l become idle, thereby preventing any low- A while the ram is being lowere ering of the ram at this time, that is to sa when the latter-llas been partially elevate It will be seen that continued rotation of the sleeve will continue elevation of the ram and when the latter has reached its; desired height, sleeve 12 is no longer rotated. When it is desired to lower the ram 10 and the weight thereon, the driving means forthe lsleeve is disconnected in a manner hereinafter described, and the weight on the ram causes lowering of the latter, causing the rotation, in a reverse direction, of the sleeve 12 in a manner which will be obvious to those sliilled in the art.

The driving or rotating means for the sleeve comprises a handle 13, clutch plates 14 and 15, and gears 16 and 17. The handle 13 is provided with left hand threads 30 which enga e the correspondingly threaded portion of te driving clutch late 14. Rotation of the handle in a right liand or clockwise direction will cause the driving clutch plate 14 to be projected forward or to the left as in Fig. 1, where it enga-ges on its clutch face 31 the driven plate 15, rotatably mounted on shaft or screw 32 on the handle 13. The driven clutch plate 15 is provided with a pinion gear 16 which engages the ring gear 17 fixed to sleeve 12, thereby causing rotation of the latter. Continued rotation of the handle, will cause sleeve 12 to rotate thereby causing continued elevation of the ram.

When theram has been elevated to its desired height, handle 13 is no longer rotated, and a stop, hereinafter described, prevents reverse rotation thereof, and consequently reverse rotation of the sleeve and lowering of the ram.

When it is desired to lower the weight, handle 13 is partially rotated in a left hand or counter clockwise direction causing the driving clutch plate 14-to back awayfrom andldisengage the driven clutch plate 15 which then freely rotates on the shaft 32 in a counter clockwise direction, the ressure of the weight on the cradle 11 an on the ram 10 causing rotation of the sleeve 12, ring gear 17, pinion gear 16 and clutch plate 15 1n a manner reviously described.

lt is desiralble to provide means to prevent rotation of the handle after the ram has been elevated to its desired hei ht and also d, the means being inoperable when the ram and the Weight are being elevated.

Fig. 2Y best shows the means I employ for this purpose. The latter comprises a ball stop 40, which is normally spring pressed into the path of the driving clutch piate 14. When driving clutch 14' rotates in a clockwise direction with the handle, that is to say,

when the ram is being elevated, the stop is inoperative to prevent rotation thereof, the plate 14 forcing ball 40 into the cylinder 41 y rotation of plate 14 thereby preventing rotation of the handlev 13. l

t will be seen, therefore, that I have provided a construction wherein the'r'am may be raised or lowered at will and wherein the 1 driving handle need be rotated only during the time when it is desired to elevate the ram, the handle beinfr non-rotatablewhen the ram isbeinglowere .Y l

It will also be noted that ,Ihaveprovided a construction wherein the ram is provided with a single turn groove instead of the multiple turn groove sometimes usedin constructions of this character, thereby reducing the cost of manufacture to a considerable extent.

Whatlclaimis:

1. An automobile jack comprising'a slidable ram, a rotatable sleevesurrounding said ram, means to prevent rotation of the ram, means to prevent reciprocation of said sleeve, and means to cause the rotation ofv said sleeve, said ram and sleeve having'cooperating formationsto enable rotation of said sleeve to cause elevation of said ram, said formations including a peripheral endless singlev turn groove on said ram, an internal helical multiturn groove on said sleeve, and a plurality of balls in the sleeve groove.

2. An automobile jack comprising a slidable ram, a rotatable sleeve surrounding said ram, means to prevent rotation of the ram, means to prevent reciprocation of said sleeve, and means to cause the rotation of saidSleeVe, said ram and slee'.'e having cooperating for; mations to enable rotation of said sleeve to cause elevation of said ram, said formations including a peripheral endless single turn groove on said ram, an internalhelical multiturn groove on said sleeve, anda plurality. of balls in the sleeve groove,fsaid ram groove comprising a downwardly inclined portion and an upwardly inclined ortion connecting the ends of said downward y inclined portion.

3. An automobile` jack comprising a slidable ram, a rotatable sleeve surrounding said ram, means to prevent rotation of the ram, means to prevent reciprocation of said sleeve, and means to cause the rotation of said sleeve having cooperating formations to enable rotation of said sleeve tocause elevation of said las inclined portion, and bein greater depth than that o inclined portion.

4. An automobile` jack comprisin a slidable ram, a rotatable sleeve surroun ing said ram, means to prevent rotation of the ram, means to prevent reciprocation of said sleeve, and means to cause the rotation of said sleeve having cooperating formations to enable rotation of said sleeve to cause elevation of said of considerably the downwardly ram, said formations including a peripheral l endless single turn groove on said ram, an internal helical multi-turn groove on said sleeve,

and a plurality of balls 1n the sleeve groove, said ram groove comprising a downwardly inclined portion and an u wardly inclined portion, connecting the en s of said downwardly inclinedV portion, and bein of considerably greater depth than that o the downwardly inclined portion, the deeper portion of said ram groove affording a path for the balls permitting the latter to ride therein and be clear of the groove on said sleeve.

NORMAN A. BEST. 

